Abrasive apparatus

ABSTRACT

Apparatus for abrasively cleaning surfaces, such as of a ship&#39;&#39;s hull block, including the surface of at least one member which serves as a rail on which a carriage is mounted, the carriage having supporting rollers engaging the upper surface of the rail and stabilizing rollers engaging opposite sides of the rail. An abrasive-slinging device is adjustably supported on the carriage and is movable manually to direct abrasive as desired over the surfaces to be cleaned. Optionally, the carriage, or the abrasive-slinging device, or both of them may be power driven, and the carriage may be mounted on a pair of parallel members of a ship&#39;&#39;s hull block which serve as rails.

States Yamamoto et a1.

[111, 3,827,187 [451 Aug. 6, 1974 ABRASIVE APPARATUS [75] Inventors: Akira Yamamoto; Dan Yoshida;

Tatsumi Onaka, all of Minoru Shiraishi, Osaka, Japan [22] Filed: Sept. 5, 1972 [21] Appl. No.: 286,042

[30] Foreign Application Priority Data Sept. 6, 1971 Japan 4668765 [52] US. Cl 51/9, 114/222, 118/305,

[51] Int. Cl. B24c 3/06 [58] Field of Search 51/8, 9;

[56] References Cited UNITED STATES PATENTS 2,415,500 2/1947 Kennison 118/305 X 3,396,423 8/1968 Hope 1 14/222 X 3,396,492 8/1971 Schcnck 51/8 3,566,543 3/1971 Fogle 51/9 3,581,441 6/1971 Hulbcrt 5 H8 Primary Examiner-Donald G. Kelly Attorney, Agent, or Firm-Farley, Forster & Farley [57] ABSTRACT Apparatus for abrasively cleaning surfaces, such as of a ships hull block, including the surface of at least one member which serves as a rail on which a carriage is mounted, the carriage having supporting rollers engaging the upper surface of the rail and stabilizing rollers engaging opposite sides of the rail. An abrasiveslinging device is adjustably supported on the carriage and is movable manually to direct abrasive as desired over the surfaces to be cleaned. Optionally, the carriage, or the abrasive-slinging device, or both of them may be power driven, and the carriage may be mounted on a pair of parallel members of a ships hull block which serve as rails.

7 Claims, 14 Drawing Figures PATENTEDMIB m 271 1 a? PATENIEmus 61974 SHEET 0F 9 PATENTEBMIG 61974 SHEH M (if 9 PATENTEDAUB m SHEU Ti [1F 9 PATENTEnAus sum SHEET 5 BF 9 SHEH 7 BF 9 PATENTEU 8 5 4 PAIENTEnaur; sum 3,827,187

sum 9 OF 9 ABRASIVE APPARATUS SUMMARY OF THE INVENTION The present invention relates to an apparatus which can be conveniently used for the abrasive removal of rust from a large body to be cleaned, having a first plate and a second rail-like plate vertically connected to said first plate, particularly from ships hull blocks before being docked and connected together.

A ships hull block has a number of box-shaped oblong spaces each bounded by an outer plate, parallel rail-like sleeper members vertically connected to the outer plate, and transverse members extending between the sleeper members. Since the surface area of each box-like space to be cleaned is very large and occupies the greater part of the secondary cleaning work area, the advent of mechanized cleaning has long been desired. At present, such cleaning work is done mainly by a power cleaning method using a portable air grinder or a manual pneumatic sand blast method. In either case, however, the worker himself has to carry the cleaner and work under severe conditions in view of the incidental blown-up rust and dirt and the heavy equipment for protection thereagainst. Further, with the power cleaning method, the cleaning function is insufficient, while with the pneumatic sand blast method the efficiency is relatively low. With either method it is impossible to expect sufficient cleaning work.

The present invention is intended to solve the abovementioned problems and proposes apparatus wherein an abrasive-slinging device is mounted on and guided by a rail-like plate possessed by a body to be cleaned itself, Le. a sleeper member in the case of said ships hull block.

Thus an abrasive apparatus according to the present invention is adapted to clean the surface of a body to be cleaned such as ships hull block having a first plate and a second rail-like plate connected to said first plate and comprises a carriage adapted to be mounted on and moved along said rail-like plate, an abrasiveslinging device supported on said carriage in such a manner as to be capable of changing the direction in which abrasives are slung, said abrasive-slinging device being provided with an impeller for slinging abrasives and a motor for driving said impeller.

According to such present inventive apparatus, the use of an abrasive-slinging device which slings abrasives by an impeller driven by a motor assures a far higher efficiency and more powerful cleaning than the conventional power cleaning method and pneumatic sand blast method. Moreover, there is no need for the worker to support the abrasive-slinging apparatus. He has only to drive the carriage mounting said device and control the slinging direction of said device, whereby the intended cleaning work can be done with less labor and continuously with respect to the lateral surface of the rail-like plate and the surface of the plate to which the rail-like plate is vertically connected. Further, economy is also achieved in that the path of movement of the carriage is determined by the rail-like plate of the body to be cleaned so that there is no need to provide a separate rail. v

According to a preferred embodiment of the present invention, the carriage mounting said abrasive-slinging device includes a plurality of longitudinally arranged upper support rollers riding on the upper end surface of the rail-like plate and lateral support rollers engaging said rail-like plate from the opposite sides thereof, and the abrasive-slinging device is supported in a cantilever fashion on one side of the carriage, one of said lateral support rollers, located on the side of the rail-like plate where the abrasive-slinging device exists, being positioned below the level of the other lateral support roller located on the other side of the rail-like plate.

Besides this arrangement wherein the carriage can be supported on and guided by a single rail-like plate, according to other embodiments of the invention, the carriage is arranged to be supported by two adjacent rail like plates. Thus, the carriage includes upper support rollers riding on the upper end surfaces of two adjacent rail-like plates and lateral support rollers for engaging one rail-like member from the opposite sides thereof, and the abrasive-slinging device is supported by being suspended in an intermediate position between the upper support rollers.

Other numerous features and merits of the present invention will be readily understood from the following description of the manner of embodying the present invention, with reference to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIGS. 1 through 4 show a first embodiment of the present invention wherein:

FIG. 1 is a schematic perspective view of the whole apparatus;

FIG. 2 is an end elevation of the apparatus;

FIG. 3 is a plan view of the apparatus; and,

FIG. 4 is a side elevation of the apparatus with part of the apparatus removed;

FIGS. 5 through 8 show a second embodiment of the invention, wherein:

FIG. 5 is a schematic perspective view of the whole apparatus;

FIG. 6 is an end elevation of the apparatus;

FIG. 7 is a plan view of the apparatus;

FIG. 8 is a side elevation of the apparatus with part of the apparatus removed;

FIGS. 9 through 14 show a third embodiment of the invention, wherein:

FIG. 9 is a schematic perspective view;

FIG. 10 is a schematic plan view;

FIG. 11 is a fragmentary end elevation;

FIG. 12 is a plan view;

FIG. 13 is a fragmentary side elevation; and,

FIG. 14 is an enlarged sectional elevation of the central portion of the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment The numeral 1 designates a body to be cleaned which is constituted by a plate member 2 and a tee member 3. When this is assumed to be a ships hull block, the plate member 2 corresponds to the outer plate of a hull and the tee member 3 corresponds to a sleeper member. The numeral 4 designates a carriage comprising a spanning rod 5 spanning the top of the tee member 3, two vertical rods 6 and 7 attached to and suspended from the opposite ends of the spanning rod 5, a lateral horizontal rod 8 attached to the lower end of the shorter one 6 of the two vertical rods 6 and 7, an upper horizontal rod 9 attached at right angles to the spanning rod 5, upper support rollers attached to the opposite ends of the upper horizontal rod 9 and rolling on the upper surface member 3a of the tee member 3, and lateral support rollers 11 and 12 attached to the opposite ends of the lateral horizontal rod 8 and to the lower portion of the longer vertical rod 7 and rolling on the lateral surfaces of the vertical support member 3b of the tee member 3. In this arrangement, the two upper support rollers 10 support the vertical load on the carriage 4, and since the two lateral support rollers 11 and the single lateral support roller 12 are vertically spaced apart a given distance S and engage the vertical support member 3b, it is possible to counteract a clockwise turning moment, as seen in FIG. 2, around a point of contact with the rollers 11 or roller 12.

Angular joints l3 interconnect the spanning rod 5 and upper horizontal rod 9, the spanning rod 5 and vertical rods 6 and 7, and the vertical rod 6 and the lateral horizontal rod 8, respectively. The numeral 14 designates a roller-attaching member. A liftable member 15 is fitted over the longer vertical rod 7 of the carriage 4. Thus, the member 15 can be fixed at any desired level by means of clamping bolts 16. Further, said member 15 has a support base or bracket 18 attached thereto through a ball joint 17. An abrasive-slinging device 19 is rotatably mounted between the pair of arms 18a of the bracket 18 by means of a transverse shaft 20 on which the abrasive-slinging device is supported. By operating (tightening and loosening) a nut 22 provided with a handle 21, the joint angle of the ball joint can be changed and the bracket 18 can be turned to any desired directin. Therefore, the combination of the ball joint 17 and transverse shaft 20 allows the abrasiveslinging apparatus 19 to take any desired slinging position. In addition, bearing portions 23 of the bracket 18 supporting the transverse shaft 20 are opened upwardly in order to facilitate the mounting and dismounting of the abrasiveslinging device 19. The abrasive-slinging device 19 has an impeller 25 adapted to be rotated by an air motor 24 to impulsively sling abrasives fed through an abrasive supply hose 26. The air motor 24 of the abrasive-slinging device 19 has an air supply hose 27 connected thereto through a handle lever 29 provided with a valve lever 28 for opening and closing the air passageway. The numeral 30 designates an abrasiveslinging region.

A cleaning method using the apparatus described above will now be described. First, the carriage 4 is mounted on the tee member 3 of the body 1 to be cleaned in the manner described above, with the two upper support rollers 10 placed on the upper surface member 3a of the tee member 3 and with the two lateral support rollers 11 and the single lateral support roller 12 engaging the vertical support member 3b of the tee member 3. The abrasive-slinging device 19 is then set on the bracket 18. At this time, the weight of the abrasive-slinging device 19 acts on the carriage in a cantilever fashion, but the device can be securely supported since the lateral support rollers are vertically spaced apart by the given distance S, as described above, with the roller 12 on the side of the abrasiveslinging device 19 being below the level of the rollers 11 on the opposite side to engage the vertical support member 3b.

In this condition, the carriage 4 is moved onthe tee member 3 while the air motor 24 is rotated and abrasives are fed and slung to clean the body 1. In this case,

the region to which abrasives are slung by the abrasiveslinging device 19 can be determined by the rotation of the device around the axis of the transverse shaft 20 whose position is preset bythe ball joint 17. The operation for the rotation of the abrasive-slinging device 19 around the axis of the transverse shaft 20, that is, the operation for a change in the abrasive-slinging position may be effected by manipulating the handle lever 29. Further, the adjustment of the vertical position of the abrasive-slinging device may be effected by moving the member 15 with respect to the vertical rod 7.

SECOND EMBODIMENT The second embodiment is a modification of the first embodiment described above and is shown in FIGS. 5

through 8. To those parts which correspond to the first embodiment are applied the same reference characters and a description of such parts will be omitted.

The second embodiment is characterized in that the clamping bolts 16 for fixing the member 15 with respect to the vertical rod 7 are omitted to render the member 15 free to move vertically with respect to the vertical rod 7, and a tension spring is provided to suspend the member 15 so as to upwardly bias the abrasive-slinging device; and, in that driving means 51 is provided for propelling the carriage 4 along the tee member 3.

As shown in FIG. 6, the tension spring 50 has one end thereof connected to the lower portion of the vertical rod 7 and the other end connected to the slide member 15 through a wire rope 52 trained over a sheave 57.

With this arrangement wherein the tension spring 50 is contained within the vertical rod 7, it is possible to protect the tension spring 50 and save space. The drive means 51 comprises a speed-reducing, reversible type motor 53 attached to the upper rod 9 of the carriage 4, a sprocket wheel 54 fixed to the motor shaft, sprocket wheels 55 each fixed to the shaft on which one of the two upper support rollers 10 is mounted, and a chain entrained around these three sprocket wheels.

When the abrasive apparatus of this embodiment is used, the power from the motor 53 can be utilized to move the carriage 4 along the tee member 3. That is, the power from the motor 53 is transmitted through the sprocket wheels 54 and 55 and chain 56 to the two upper support rollers 10 to drive them, so that if the rotative speed and the direction of rotation of the motor 53 are controlled, it is possible to move the carriage forwardly or backwardly at any desired speed.

As in the case of the first embodiment, the abrasiveslinging device 19 can be rotated around the axis of the transverse shaft 20 by manipulating the handle lever 29, but it is also possible to raise and lower the abrasive-slinging device 19 together with the slide member 15 along the vertical rod 7 by raising and lowering the handle lever 29. Moreover, the raising and lower operation of the abrasive-slinging device 19 is greatly facilitated by the tension spring 50 acting as a balancer for the abrasive-slinging device 19.

In addition, the slide member 15 in this embodiment may be designed to be fixed at any desired level, as in the case-of the first embodiment. Further, either the drive means 51 for the carriage 4 or the tension spring 50 for upwardly biasing the abrasive-slinging device 19 may be added to the cleaning apparatus of the first embodiment.

THIRD EMBODIMENT A third embodiment will now be described with reference to FIGS. 9 through 14.

In FIGS. 9 and 10, a ships hull block 101 consists of an outer plate 102, parallel sleepers 103A and 1038 vertically connected to said outer plate 102, and transverse members 104 extending between the sleepers 103A and 103B, thus forming a number of box-shaped portions 105.

A framework 106 supporting an abrasive-slinging device 107 spans the space between the sleepers 103A and 1038 and is arranged to be movable back and forth in the lengthwise direction A of the lounges 103A and 1038 with the sleepers 103A and 1038 serving as guides. As shown in FIGS. 11 through 14, the framework 106 is constructed by assembling transverse pipes 108 and longitudinal pipes 109, and has a traveling motor base 110 fixed on one side thereof and a roller support plate 111 fixed on the other side. Rollers 112 riding on one sleeper 103A are journaled on the motor traveling base 110 and a roller 113 riding on the other sleeper 1038 is journaled on the roller support plate 111. The traveling motor base 110 and the roller support plate 111 are connected to the transverse pipes 108 through joints 114 which are capable of being tightened and loosened, making it possible to change the distance B between the rollers 112 and 113. A traveling air motor 115 is mounted on the motor base 110. A chain 119 is entrained around a transmission sprocket wheel 116 and an intermediate large sprocket wheel 117 journaled on said traveling motor base 110 and a chain 120 driven by said intermediate large sprocket wheel 117 is entrained around driven sprocket wheels 118 integral with the rollers 112, thereby making it possible to drive the rollers 112. These members 112 and 115 through 120 constitute drive means 121 for moving the framework 106 in the lengthwise direction A of the sleepers 103A and 103B.

Rollers 122a and 122b which engage one sleeper 103A are provided on one side of the framework 106. That is, a pair of front and back rollers 122 are disposed outside the traveling motor base 110 and abut against the outer surface 103a of the sleeper 103A, while a single roller 122b is disposed inside the traveling motor base 110 and abuts against the inner surface 103a of the sleeper 103A. These rollers engage the sleeper 103A in such a manner that their center distances form an isosceles triangle. Further, these rollers 122a and 122b are attached to the transverse pipes 108 through joints 123a and 123b which are capable of being tightened and loosened, so that they can be moved toward and away from each other in the lengthwise direction of the transverse pipes 108.

An abrasive-slinging device 107 is supported on a base 124 attached to the middle portion of the framework 106. The base 124 is attached to the lower ends of four vertical pipes 126 liftable with respect to joints 125 attached to the transverse pipes 108, said joints 125 being movable lengthwise of the transverse pipes 108. Therefore, the base 124 for the abrasive-slinging device 107 is liftable with respect to the framework 106 and movable widthwise (or transversely) of the framwork. Further, the abrasive-slinging device 107 is fixed to the lower end of a vertical shaft 127 rotatably attached to the base 124, so that the device is rotatable around the vertical axis 127a. The numeral 128 designates means for effecting the rotation of the abrasiveslinging device 107, said means comprising an air motor 129 mounted on said base 124, a drive sprocket wheel 131 operatively connected to said air motor through a speed reducer 130, and a driven sprocket wheel 133 attached to the upper end of the vertical shaft 127 and operatively connected to said driven sprocket wheel 131. The rotative speed may be changed by replacing the driven sprocket wheel 133 by a selected one having a different diameter.

The abrasive-slinging device 107 comprises a casing 134 integral with the vertical shaft 127, an air motor 135 attached to one lateral wall of said casing 134, an impeller 137 attached to the air motor shaft 136 and disposed within said casing 134, and an abrasive-feed pipe 138 attached to the other lateral wall of the casing and opening to the center of said impeller 137. An abrasive-slinging port 139 formed in the casing 138 is unsymmetrical and, as shown in FIG. 11, can be switched over to an abrasive-slinging angle C extending from the inner lateral wall 103a of one sleeper 103A to the upper surface 102a of the outer plate 102 or to an abrasiveslinging angle D extending from the inner lateral surface 1031) of the other sleeper 1038 to the upper surface 102a of the outer plate 102.

The operation will now be described.

After the distance B between the rollers 1 l2 and 113 has been adjusted to the distance between the sleepers 103A and 103B to be spanned by the framework 106, these rollers 112 and 113 are placed on the corresponding sleepers 103A and 1038. The rollers 122a and 12% which have been sufficiently spaced apart from each other in advance are adjusted toward each other until they abut against the outer and inner lateral surfaces 103a and 103a of one sleeper 103A to clamp said one sleeper 103A. When the drive means 121 is started, the framework 106 is moved as guided by the sleepers 103A and 1038 in the sleeper length direction A. At this time, if the abrasive-slinging device has been driven, abrasives slung through the abrasive-slinging port 139 are blown against the inner lateral surfaces 103a and 103b of the sleepers 103A and 1038 and against the upper surface 102a of the outer plate 102, whereby cleaning of these surfaces 103a, 103b and 102a forming the box-like portion is effected. In this way, the cleaning operation is progressively carried out with the movement of the framework 106, but in this case the intended cleaning operation may be completed in a single process by rotating the abrasiveslinging device 107 around the axis 0f.pthe vertical shaft 127a. Alternatively, as shown in FIG. 11, the cleaning operation on one side may be effected by the abrasiveslinging angle C in going and the remaining cleaning operation on the other side may be effected by the abrasive-slinging angle D in coming back. These cleaning operations will be suitably selected depending upon the rusted state of work, the force with which to sling abrasives, the amount of abrasives slung, and the traveling speed of the framework.

We claim:

1. Apparatus for cleaning the surface of a body such as a ships hull block having a first plate and a second rail-like plate connected to said first plate, comprising:

a carriage adapted to ride on said rail-like plate and to travel along said rail-plate, said carriage including a plurality of longitudinally arranged rollers adapted to engage the upper end surface of said rail-like plate, and including lateral support rollers adapted to engage said rail-like plate from the opposite sides thereof;

an abrasive-slinging device, means for supporting the abrasive-slinging device on one side of said carriage in a cantilever fashion in such a manner as to be capable of changing the direction in which abrasives are slung, said abrasive-slinging device being provided with an impeller for slinging abrasives supplied and a motor for driving said impeller; and,

the lateral support roller on the side of the rail-like plate where the abrasive-slinging device exists being located below the level of the lateral support roller on the other side of the rail-like plate.

2. Apparatus as set forth in claim 1 wherein the distance between said lateral support rollers is adjustable.

3. Apparatus for cleaning the surface of a body such as a ships hull block having a first plate and two adjacent rail-like plates connected to said first plate, comprising:

a carriage adapted to ride on said rail-like plates and capable of travelling along said rail-like plates, said carriage including upper support rollers adapted to ride on the upper end surfaces of two adjacent raillike plates, and lateral support rollers adapted to engage one of said rail-like plates from the opposite sides thereof;

an abrasive-slinging device, means for supporting the abrasive-slinging device on said carriage in such a manner as to be capable of changing the direction in which abrasives are slung, said supporting means suspending the abrasive-slinging device from the carriage at a position intermediate said upper support rollers, said abrasive-slinging device being provided with an impeller for slinging abrasives supplied and a motor for driving said impeller.

4. Apparatus for cleaning the surface of a body such as a ships hull block having a first plate and a second rail-like plate connected to said first plate, comprising:

a carriage adapted to ride on said rail-like plate and capable of travelling along said rail-like plate; an abrasive-slinging device, means for supporting the abrasive-slinging device on said carriage liftably with respect thereto in such a manner as to be capable of changing the direction in which abrasives are slung, said abrasive-slinging device being provided with an impeller for slinging abrasives supplied and a motor for driving said impeller; and,

said means for supporting the abrasive-slinging device including a balancer which upwardly biases said abrasive-slinging device, said balancer including a tension spring disposed within a pipe-like vertical rod and having the lower end thereof fixed to said vertical rod, and a wire rope fixed at one end thereof to the upper end of said tension spring and downwardly guided out of said vertical rod by means of a sheave disposed on the upper end of said vertical rod, said wire rope suspending said abrasive-slinging device.

5. Apparatus as set forth in claim 3, wherein the distance between the upper support rollers riding on the upper end surfaces of said two rail-like plates is adjustable.

6. Apparatus as set forth in claim 1, wherein the means for supporting the abrasive-slinging device includes a support base on which the abrasive-slinging device is pivotally mounted for swinging motion, a ball joint supporting said support base in such a manner as to permit the support base to be directed in any desired direction, and said abrasive-slinging device is provided with a handle lever.

7. Apparatus as set forth in claim 3, wherein the abrasive-slinging device is rotatable around a vertical axis and there is provided drive means for effecting such rotation. 

1. Apparatus for cleaning the surface of a body such as a ship''s hull block having a first plate and a second rail-like plate connected to said first plate, comprising: a carriage adapted to ride on said rail-like plate and to travel along said rail-plate, said carriage including a plurality of longitudinally arranged rollers adapted to engage the upper end surface of said rail-like plate, and including lateral support rollers adapted to engage said rail-like plate from the opposite sides thereof; an abrasive-slinging device, means for supporting the abrasiveslinging device on one side of said carriage in a cantilever fashion in such a manner as to be capable of changing the direction in which abrasives are slung, said abrasive-slinging device being provided with an impeller for slinging abrasives supplied and a motor for driving said impeller; and, the lateral support roller on the side of the rail-like plate where the abrasive-slinging device exists being located below the level of the lateral support roller on the other side of the rail-like plate.
 2. Apparatus as set forth in claim 1 wherein the distance between said lateral support rollers is adjustable.
 3. Apparatus for cleaning the surface of a body such as a ship''s hull block having a first plate and two adjacent rail-like plates connected to said first plate, comprising: a carriage adapted to ride on said rail-like plates and capable of travelling along said rail-like plates, said carriage including upper support rollers adapted to ride on the upper end surfaces of two adjacent rail-like plates, and lateral support rollers adapted to engage one of said rail-like plates from the opposite sides thereof; an abrasive-slinging device, means for supporting the abrasive-slinging device on said carriage in such a manner as to be capable of changing the direction in which abrasives are slung, said supporting means suspending the abrasive-slinging device from the carriage at a position intermediate said upper support rollers, said abrasive-slinging device being provided with an impeller for slinging abrasives supplied and a motor for driving said impeller.
 4. Apparatus for cleaning the surface of a body such as a ship''s hull block having a first plate and a second rail-like plate connected to said first plate, comprising: a carriage adapted to ride on said rail-like plate and capable of travelling along said rail-like plate; an abrasive-slinging device, means for supporting the abrasive-slinging device on said carriage liftably with resPect thereto in such a manner as to be capable of changing the direction in which abrasives are slung, said abrasive-slinging device being provided with an impeller for slinging abrasives supplied and a motor for driving said impeller; and, said means for supporting the abrasive-slinging device including a balancer which upwardly biases said abrasive-slinging device, said balancer including a tension spring disposed within a pipe-like vertical rod and having the lower end thereof fixed to said vertical rod, and a wire rope fixed at one end thereof to the upper end of said tension spring and downwardly guided out of said vertical rod by means of a sheave disposed on the upper end of said vertical rod, said wire rope suspending said abrasive-slinging device.
 5. Apparatus as set forth in claim 3, wherein the distance between the upper support rollers riding on the upper end surfaces of said two rail-like plates is adjustable.
 6. Apparatus as set forth in claim 1, wherein the means for supporting the abrasive-slinging device includes a support base on which the abrasive-slinging device is pivotally mounted for swinging motion, a ball joint supporting said support base in such a manner as to permit the support base to be directed in any desired direction, and said abrasive-slinging device is provided with a handle lever.
 7. Apparatus as set forth in claim 3, wherein the abrasive-slinging device is rotatable around a vertical axis and there is provided drive means for effecting such rotation. 